Dispensing valve

ABSTRACT

A flexible, resilient, slit valve ( 10 ) including a flexible, resilient head ( 12 ) centered on a central axis ( 27 ) and extending laterally therefrom, an annular, peripheral attachment portion ( 19 ) centered on the central axis, and an annular, flexible, resilient, intermediate portion ( 20 ). The head has a convex interior surface ( 16 ) and a concave exterior surface ( 14 ). The intermediate portion ( 20 ) has an interior surface ( 26 ) an exterior surface ( 24 ). The exterior surfaces ( 14, 24 ) intersect at a circular line of intersection ( 32 ) having a diameter D 1 . The exterior surface ( 24 ) and the peripheral attachment portion ( 19 ) intersect at a circular line of intersection ( 34 ) having a diameter D 2 . The lines of intersection ( 32, 34 ) lie in parallel planes extending transverse to the central axis ( 27 ) and spaced from each other along the central axis by a distance L 1 . The ratio of D 1 /D 2  is in the range of 0.600 to 0.900 and the ratio of D 2 /L 1  is in the range of 14.000 to 19.000 in an as-molded condition of the valve ( 10 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

MICROFICHE/COPYRIGHT REFERENCE

Not Applicable.

FIELD OF THE INVENTION

The present invention relates generally to dispensing valves andsystems, and more particularly relates to valves for dispensing aproduct from a container or other source, and in more particularapplications, to such valves suitable for use in a dispensing closurefor a flexible container which is squeezable to create a pressuredifferential across the valve.

BACKGROUND OF THE INVENTION

One type of flexible, resilient, dispensing valve is a self-closing,slit-type valve mounted by a closure in a port of a fluent container orother source of fluent product. Such valves have a slit or slits whichdefine a normally closed orifice that opens to permit flow therethroughin response to an increased pressure differential across the valve(e.g., resulting from an increased pressure within the container whenthe container is squeezed, or from a reduced external ambient pressurecompared to the pressure within the container). Such valves aretypically designed so that they automatically close to shut off flowtherethrough upon a reduction of the pressure differential across thevalve.

Designs of such valves and of closures using such valves are illustratedin the U.S. Pat. No. 5,271,531, No. 5,927,566, No. 5,934,512 and No.6,405,901. Typically, the closure includes a body or base mounted on thecontainer neck to define a seat for receiving the valve and includes aretaining ring or other structure for holding the valve on the seat inthe base. See, for example, U.S. Pat. No. 6,269,986 and No. 6,616,016.The valve is normally closed and can withstand the weight of the fluidproduct when the container is completely inverted so that the liquidwill not leak out unless the container is squeezed. With such a system,the lid or cap need not be re-closed (although it is typically re-closedif the package is to be transported to another location, packed in asuitcase, etc.).

While such valves and valve systems have significant advantages andfunction well, there is always room for improvement. For example, insome applications it is desirable for such valves to open in a “gentle”or non-abrupt manner with reduced splatter and more control of a fluentproduct when dispensing than is achieved with currently availablevalves.

SUMMARY OF THE INVENTION

In accordance with one feature of the invention, a flexible, resilientslit valve is provided to allow selective dispensing of a fluent productfrom an interior environment to an exterior environment. The valveincludes a flexible, resilient head centered on a central axis andextending laterally therefrom, an annular, peripheral attachment portioncentered on the central axis and spaced laterally from the head, and anannular, flexible resilient, intermediate portion centered on thecentral axis and extending laterally from the head to the peripheralattachment portion. The head has a convex interior surface to face aninterior environment; a concave exterior surface to face an exteriorenvironment; at least one self-sealing slit through the head;confronting, openable portions along the at least one slit to define anormally closed orifice in an unconstrained condition wherein theopenable portions can move in a first direction toward the exteriorenvironment to an open orifice configuration and return in an oppositedirection to a closed configuration; and a laterally outwardly facingperipheral surface extending from the interior surface toward theexterior surface, the peripheral surface being centered on the centralaxis. The intermediate portion has an interior surface to face aninterior environment, and an exterior surface to face an exteriorenvironment. The exterior surfaces of the head and the intermediateportion intersect at a first circular line of intersection having adiameter D₁. The exterior surface of the intermediate portion and theperipheral attachment portion intersect at a second interior circularline of intersection having a diameter D₂. The second circular line ofintersection is spaced in the first direction from the first circularline of intersection. The first and second circular lines ofintersection lie in parallel planes extending transverse to the centralaxis and are spaced from each other along the central axis by a distanceL₁. The ratio of D₁/D₂ is in the range of 0.600 to 0.900 in an as-moldedcondition of the valve, and the ratio of D₂/L₁ is in the range of 14.000to 19.000 in said as-molded condition of the valve.

In one feature, the exterior surface of the intermediate portion isconvex and the exterior surface of the head is concave and the firstcircular line of intersection is defined at an inflection point betweenthe convex exterior surface of the intermediate portion and the concaveexterior surface of the head.

As one feature, the ratio of D₂/L₁ is in the range of 15.500 to 16.000in the as-molded condition of the valve.

According to one feature, the ratio of D₂/L₁ is 15.750 in the as-moldedcondition of the valve.

In one feature, the ratio of D₂/L₁ is in the range of 18.500 to 19.000in the as-molded condition of the valve.

According to one feature, the ratio of D₂/L₁ is 18.750 in the as-moldedcondition of the valve.

As one feature, the ratio of D₁/D₂ is in the range of 0.625 to 0.675 inthe as-molded condition of the valve.

In one feature, the ratio of D1/D2 is 0.653 in the as-molded conditionof the valve.

As one feature, the ratio of D₁/D₂ is in the range of 0.800 to 0.850 inthe as-molded condition of the valve.

According to one feature, the ratio of D₁/D₂ is 0.827 in the as-moldedcondition of the valve.

In one feature, the ratio of D₂/L₁ is in the range of 15.500 to 16.000,and the ratio of D₁/D₂ is in the range of 0.625 to 0.675 in theas-molded condition of the valve.

As one feature, the ratio of D₂/L₁ is in the range of 18.500 to 19.000,and the ratio of D₁/D₂ is in the range of 0.800 to 0.850 in theas-molded condition of the valve.

In one feature, the intermediate portion has a uniform materialthickness separating the exterior and interior surfaces.

As one feature, the interior surface of the intermediate portion isconcave, and the peripheral surface of the head is frustoconical.

According to one feature, at least one of the interior and exteriorsurfaces of the head has a planar portion adjacent the central axis,extending transverse to the central axis.

In accordance with another feature of the invention, a flexible,resilient slit valve is provided to allow selective dispensing of afluent product from an interior environment to an exterior environment.The valve includes a flexible, resilient head centered on a central axisand extending laterally therefrom, an annular, peripheral attachmentportion centered on the central axis and spaced laterally from the head,and an annular, flexible resilient, intermediate portion centered on thecentral axis and extending laterally from the head to the peripheralattachment portion. The head has a convex interior surface to face aninterior environment, a concave exterior surface to face an exteriorenvironment, at least one self-sealing slit through the head,confronting, openable portions along the at least one slit to define anormally closed orifice in an unconstrained condition wherein theopenable portions can move in a first direction toward the exteriorenvironment to an open orifice configuration and return in an oppositedirection to a closed configuration, and a laterally outwardly facingperipheral surface extending from the interior surface toward theexterior surface, the peripheral surface centered on the central axis.The intermediate portion has an interior surface to face an interiorenvironment, and an exterior surface to face an exterior environment.The interior surface of the intermediate portion and the peripheralsurface of the head intersect at a third circular line of intersectionhaving a diameter D₃. The interior surface of the intermediate portionand the peripheral attachment portion intersect at a fourth circularline of intersection having a diameter D₄. The fourth circular line ofintersection is spaced in the first direction from the third circularline of intersection. The third and fourth circular lines ofintersection lie in parallel planes extending transverse to the centralaxis and are spaced from each other along the central axis by a distanceL₂. The ratio of D₃/D₄ is in the range of 0.600 to 0.900 in an as-moldedcondition of the valve, and the ratio of D₄/L₂ is in the range 14.00 to30.00 in an as-molded condition of the valve.

In one feature, the ratio of D₃/D₄ is in the range of 0.650 to 0.700 inan as-molded condition of the valve.

In one feature, the ratio D₃/D₄ is 0.681 in an as-molded condition ofthe valve.

In one feature, the ratio of D₄/L₂ is in the range of 14.5 to 15.5 in anas-molded condition of the valve.

As one feature, the ratio of D₄/L₂is 14.921 in an as-molded condition ofthe valve.

As one feature, the ratio of D₃/D₄ is in the range of 0.850 to 0.950 inan as-molded condition of the valve.

According to one feature, the ratio D₃/D₄ is 0.867 in an as-moldedcondition of the valve.

In one feature, the ratio of D₄/L₂ is in the range of 29 to 31 in anas-molded condition of the valve.

As one feature, the ratio of D₄/L₂ is 30.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention, from the claims, and from the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings forming part of the specification, in whichlike numerals are employed to designate like parts throughout the same.

FIG. 1 is a top plan view of a valve embodying the present invention;

FIG. 2 is a cross-sectional view taken from line 2-2- in FIG. 1;

FIG. 3 is an isometric view from above of the valve of FIGS. 1 and 2;

FIG. 4 is a fragmentary, cross-sectional view of the valve of FIGS. 1-3installed in a closure and showing the valve in a closed condition;

FIG. 5 is a view similar to FIG. 4, but showing the valve in an opencondition;

FIG. 6 is a greatly enlarged fragmentary, cross-sectional view of aportion of the valve shown in FIG. 2; and

FIG. 7 is a graphical representation showing the test results of aControl of Dispense test comparing valves made according to theinvention to conventional valves.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible of embodiment in many differentforms, this specification and the accompanying drawings disclose onlyone specific form as an example of the invention. The invention is notintended to be limited to the embodiment so described, however. Thescope of the invention is pointed out in the appended claims.

For ease of description, the valve of this invention may be described,along with a closure, in a typical (upright) position, and terms such asupper, lower, horizontal, etc., are used with reference to thisposition. It will be understood, however, that the valve embodying thisinvention may be manufactured, stored, transported, used, and sold in anorientation other than the position described.

Figures illustrating the valve of this invention and the associatedclosure show some conventional mechanical elements that are known andthat will be recognized by one skilled in the art. The detaileddescriptions of such elements are not necessary to an understanding ofthe invention, and accordingly, are herein presented only to the degreenecessary to facilitate an understanding of the novel features of thepresent invention.

A presently preferred embodiment of a valve according the invention isillustrated in FIGS. 1-6 and is designated generally by the number 10.The valve 10 is a self-closing, slit-type valve and is preferably moldedas a unitary structure from material which is flexible, pliable,elastic, and resilient. This can include elastomers, such as asynthetic, thermosetting polymer, including silicone rubber, such as thesilicone rubber sold by Dow Corning Corp. in the United States ofAmerica under the trade designations DC-99-595 and RBL-9595-40. Both ofthese materials have a hardness rating of 40 Shore A. The valve 10 canalso be molded from other thermosetting materials or from otherelastomeric materials, or from thermoplastic polymers or thermoplasticelastomers, including those based upon materials such as thermoplasticpropylene, ethylene, urethane, and styrene, including their halogenatedcounterparts.

The valve 10 includes a flexible, resilient central portion or head 12having a first or exterior surface 14 facing an exterior environment(shown generally at 15 in FIGS. 2, 4, and 5) and a second or interiorsurface 16 (FIGS. 2, 4, and 6) facing an interior environment (showngenerally at 17 in FIGS, 2, 4, and 5). The head 12 also has a laterallyoutwardly facing peripheral surface 18 (FIGS. 2, 4, and 6) extendingfrom the interior surface 16 toward the exterior surface 14, and in theillustrated and preferred embodiment the peripheral surface 18 isfrustoconical.

The valve 10 further includes a peripheral attachment portion or flange19, and a flexible, resilient intermediate portion or sleeve 20 thatextends laterally outwardly from the head 12 to the flange 19.Hereinafter, the term “sleeve” 20 is used in this specification, but inthe claims the term “intermediate portion” 20 is used. The sleeve 20 hasan exterior surface 24 (FIGS. 1-4, and 6) and interior surface 26 (FIGS.2, 4, and 6) that, in the illustrated and preferred embodiment, areseparated by a uniform material thickness T (FIG. 1) of the sleeve 20.

The head 12, peripheral attachment portion 19, and sleeve 20 arepreferably all symmetrical bodies of revolution centered on a centralaxis 27. Preferably and as illustrated, the exterior surface 14 of thehead 12 is concave, the interior surface 16 of the head 12 is convex,the exterior surface 24 of the sleeve 20 is convex, and the interiorsurface 26 of the sleeve 20 is concave. In the illustrated embodiment,the convex, interior surface 16 of the head 12 includes a planar portion16A (FIGS. 2 and 6) extending transversely from the central axis 27 overa limited area adjacent the axis 27.

As best seen in FIGS. 1 and 3, the head 12 has planar, intersecting,self-sealing slits 28 which together define a closed orifice when thevalve 10 is in the closed condition. For purpose of illustration, theslits 28 are each shown in FIGS. 1, 2, 3 and 6 as defining an open slot.However, it will be understood that in the as-molded, closed conditionof the valve 10, each slit 28 is closed and does not define an openslot. Preferably, the slits 28 are normal to each other and equal inlength. In the illustrated form of the valve 10, the slits 28 definefour, generally sector-shaped, equally sized flaps or petals 30 in thehead 12. The flaps or petals 30 may also be characterized as “openableregions” or “openable portions” of the valve head 12. Each flap or petal30 has a pair of diverging transverse faces 31 defined by the slits 28,and each transverse face seals against a confronting transverse face 31of an adjacent petal 30 when the valve 16 is closed (faces 31 shownspaced from each other in some of the figures for purposes ofillustration only). The valve 10 can be molded with the slits 28, oralternatively, the slits 28 can be subsequently cut into the head 12 ofthe valve 10 by suitable conventional techniques. As anotheralternative, the slits 28 could be partially molded into the head 12,with the remainder being cut after molding.

The valve 10 has a normally closed, rest position or configuration shownin FIGS. 1-4 and 6. The valve 10 is typically designed to remain closedwhen the pressure differential across the valve head 12 is below apredetermined amount, with the petals 30 defining a normally closedorifice configuration. The valve 10 can be forced to one or more openpositions or configurations, as shown in FIG. 5, when a sufficientlyhigh dispensing pressure differential is applied across the valve 12thereby moving the petals 30 in a first or opening direction toward theexterior environment to an open orifice configuration. When the pressuredifferential across the valve 110 is decreased sufficiently, theinherent resiliency of the valve 10 allows the valve 10 to return to thenormally closed condition (by action of the force generated from theresilient valve's deformational stresses).

The exterior surfaces 14 and 24, respectively, of the head 12 and sleeve20 intersect at a first circular line of intersection, showndiagrammatically at 32 in FIGS. 1-4 and 6, having a diameter D₁ (FIG. 1)and which is defined at an inflection point between the convex exteriorsurface 24 and the concave exterior surface 14 in the illustrated andpreferred embodiment. The exterior surface 24 of the sleeve 20intersects the peripheral attachment portion 19 at a second circularline of intersection, shown diagrammatically at 34 in FIGS. 1-4 and 6,having a diameter D₂ (FIG. 1). The peripheral surface 18 of the head 12and the interior surface 26 of the sleeve 20 intersect at a thirdcircular line of intersection 36 (FIGS. 2, 4, and 6) having a diameterD₃ (FIG. 1), and the interior surfaces 26 of the sleeve 20 intersectsthe peripheral attachment portion 19 at a fourth circular line ofintersection 38 (FIGS. 2, 4, and 6) having a diameter D₄ (FIG. 1).

The second circular line of intersection 34 is spaced in the firstdirection (toward the exterior environment 15) from the first circularline of intersection 32. The fourth circular line 38 of intersection isspaced in the first direction from the third circular line ofintersection 36. The first, second, third, and fourth circular lines ofintersection 32, 34, 36, and 38 lie in parallel planes extendingtransverse to the central axis 27, with the first and second circularlines of intersection 32 and 34 being spaced from each other along thecentral axis 27 by a distance L₁, (FIG. 1) and the third and fourthcircular lines of intersection 36 and 38 begin spaced from each otheralong the central axis 27 by a distance L₂ (FIG. 1).

The inventors of the present invention have discovered that a “gentle”or non-abrupt opening of the valve 10 with reduced splatter and morecontrol of a fluent product can be achieved by controlling the distanceL₁ with respect to the diameters D₁ and D₂, and/or by controlling thedistance L₂ with respect to the diameters D₃ and D₄, with all of thedistances and diameters being controlled in the as-molded condition orstate of the valve 10 (e.g. the condition or state of the valve 10 asdefined by the mold and without external forces being applied to thevalve 10). More specifically, it has been discovered that controllingthe ratio of D₂/L₁ and/or the ratio of D₁/L₁ with respect to the ratioof D₁/D₂, and/or controlling the ratio D₄/L₂ and/or the ratio of D₃/L₂with respect to the ratio D₃/D₄, produces the desirable result of a“gentle” opening of the valve 10 with reduced spatter and more controlof a fluent product during dispensing.

In preferred embodiments of the valve 10, the ratio of D₂/L₁ is in therange of 14.000 to 19.000 in the as-molded condition of the valve 10with respect to ratios of D₁/D₂ in the range of 0.600 to 0.900 in theas-molded condition of the valve 10. In some more preferred embodimentsof the valve 10, the ratio of D₂/L₁ is in the range of 18.500 to 19.000in the as-molded condition of the valve 10 with respect to ratios ofD₁/D₂ in the range of 0.600 to 0.900 in the as-molded condition of thevalve 10, and even more preferably, with respect to ratios of D₁/D₂ inthe range of 0.800 to 0.850 in the as-molded condition of the valve 10,especially when molded from the previously identified silicone rubbermaterial. In some highly preferred embodiments of the valve 10, theratio of D₂/L₁ is in the range of 15.500 to 16.000 in the as-moldedcondition of the valve 10 with respect to ratios of D₁/D₂ in the rangeof 0.600 to 0.900 in the as-molded condition of the valve 10, and evenmore preferably, with respect to ratios of D₁/D₂ in the range of 0.625to 0.675 in the as-molded condition of the valve 10, especially whenmolded from the previously identified silicone rubber material.

Furthermore, in preferred embodiments of the valve 10, the ratio ofD₁/L₁ is in the range of 10.000 to 16 000 in the as-molded condition ofthe valve 10 with respect to ratios of D₁/D₂ in the range of 0.600 to0.900 in the as-molded condition of the valve 10. In some more preferredembodiments of the valve 10, the ratio of D₁/L₁ is in the range of15.000 to 16.000 in the as-molded condition of the valve 10 with respectto ratios of D₁/D₂ in the range of 0.600 to 0.900 in the as-moldedcondition of the valve 10, and even more preferably, with respect toratios of D₁/D₂ in the range of 0.800 to 0.850 in the as-moldedcondition of the valve 10, especially when molded from the previouslyidentified silicone rubber material. In some highly preferredembodiments of the valve 10, the ratio of D₁/L₁ is in the range of10.000 to 10.500 in the as-molded condition of the valve 10 with respectto ratios of D₁/D₂ in the range of 0.600 to 0.900 in the as-moldedcondition of the valve 10, and even more preferably, with respect toratios of D₁/D₂ in the range of 0.625 to 0.675 in the as-moldedcondition of the valve 10, especially when molded from the previouslyidentified silicone rubber material.

Turning to other previously mentioned ratios, in preferred embodimentsof the valve 10, the ratio of D₄/L₂ is in the range of 14.500 to 30.500in the as-molded condition of the valve 10 with respect to ratios ofD₃/D₄ in the range of 0.625 to 0.925 in the as-molded condition of thevalve 10. In some more preferred embodiments of the valve 10, the ratioof D₄/L₂ is in the range of 29.500 to 30.500 in the as-molded conditionof the valve 10 with respect to ratios of D₃/D₄ in the range of 0.625 to0.925 in the as-molded condition of the valve 10, and even morepreferably, with respect to ratios of D₃/D₄ in the range of 0.825 to0.900 in the as-molded condition of the valve 10, especially when moldedfrom the previously identified silicone rubber material. In some highlypreferred embodiments of the valve 10, the ratio of D₄/L₂ is in therange of 14.500 to 15,500 in the as-molded condition of the valve 10with respect to ratios of D₃/D₄ in the range of 0.625 to 0.925 in theas-molded condition of the valve 10, and even more preferably, withrespect to ratios of D₃/D₄ in the range of 0.650 to 0.750 in theas-molded condition of the valve 10, especially when molded from thepreviously identified silicone rubber material.

Furthermore, in preferred embodiments of the valve 10, the ratio ofD₃/L₂ is in the range of 9.500 to 26.500 in the as-molded condition ofthe valve 10 with respect to ratios of D₃/D₄ in the range of 0.625 to0.925 in the as-molded condition of the valve 10. In some more preferredembodiments of the valve 10, the ratio of D₃/L₂ is in the range of25.500 to 26.500 in the as-molded condition of the valve 10 with respectto ratios of D₃/D₄ in the range of 0.625 to 0.925 in the as-moldedcondition of the valve 10, and even more preferably, with respect toratios of D₃/D₄ in the range of 0.825 to 0.900 in the as-moldedcondition of the valve 10, especially when molded from the previouslyidentified silicone rubber material. In some highly preferredembodiments of the valve 10, the ratio of D₃/L₂ is in the range of 9.500to 10.500 in the as-molded condition of the valve 10 with respect toratios of D₃/D₄ in the range of 0.625 to 0.925 in the as-moldedcondition of the valve 10, and even more preferably, with respect toratios of D₃/D₄ in the range of 0.650 to 0.750 in the as-moldedcondition of the valve 10, especially when molded from the previouslyidentified silicone rubber material.

By design, the intermediate portion or sleeve 20 is more flexible thanthe peripheral portion of the head 12 from which the intermediateportion or sleeve 20 extends. This flexibility allows some axialtranslation of the head 12 along the central axis 27 and further allowsthe intersection of the sleeve 20 with the head 12 to act somewhat likea hinge for each of the pedals 30 of the head 12 as the pedals 30 movebetween the closed and open positions. In this regard, the materialthickness T of the sleeve 20 is less than the material thickness of theperipheral portion of the head 12 from which the intermediate portion orsleeve 20 extends, and in the preferred embodiments described above theratio of D₁/T and/or D₃/T is in the range of 15.000 to 55.000 in theas-molded condition of the valve 10, and in more preferred embodimentsthe ratio of D₁/T and/or D₃/T is in the range of 28.000 to 48.000 in theas-molded condition of the valve 10, and in highly preferred embodimentsthe of D₁/T and/or D₃/T is in the range of 17.000 to 23.000 in theas-molded condition of the valve 10, especially when molded from thepreviously identified silicone rubber material. Alternatively, in thepreferred embodiments described above the ratio of D₂/T and/or D₄/T isin the range of 25.000 to 65.000 in the as-molded condition of the valve10, and in more preferred embodiments the ratio of D₂/T and/or D₄/T isin the range of 35.000 to 47.000 in the as-molded condition of the valve10, and in highly preferred embodiments the of D₂/T and/or D₄/T is inthe range of 25.000 to 40.000 in the as-molded condition of the valve10, especially when molded from the previously identified siliconerubber material.

Testing of valves made according to the invention has shown significantimprovement in achieving the desired “gentle” dispensing in comparisonto conventional, currently available valves. For example, a SplatterEvaluation Test was performed to compare valves made according to theinvention to conventional valves. This testing showed that the valvesmade according to the invention produced a splatter area that was 52% to28% the size of the splatter area produced by conventional valves, withthe percent improvement varying from greater (52%) to smaller (28%) asthe rate of dispense increases. Additionally, FIG. 7 illustrates theresults of a Control of Dispense test wherein the amount of fluentproduct dispensed are measured with respect to time for a fixed rate ofsqueeze of a squeezable container on which the valves are mounted by aclosure during testing. As seen in FIG. 7, the valves made according tothe invention provide a more gradual increase in dispense rate with noinitial “burst” of fluent product, as shown by the gentle curve upwardsof the dispense amount for the valves made according to the invention incomparison to the initial steep slope of the dispense amount for theconventional valves.

In one specific preferred embodiment of the valve 10, especially whenmolded from the previously identified silicone rubber material,D₂/L₁=18.750, D₁/L₁=15.500, D₁/D₂=0.827, D₄/L₂=30.000, D₃/L₂=26.000,D₃/D₄=0.867, D₁/T=35.420, D₂/T=42.857, D₃/T=37.143, D₄/T=42.857, and inone preferred form of this embodiment D₁=0.238 inch, D₂=0.300 inch,D₃=0.260 inch, D₄=0.300 inch, L₁=0.016 inch, L₂=0.10 inch, and T=0.007inch.

In one highly preferred embodiment of the valve 10 which is molded fromthe previously identified silicone rubber material, and whose ratiosmatch those in the FIGS., D₂/L₁=15.750, D₁/L₁=10.278, D₁/D₂=0.653,D₄/L₂=14.921, D₃/L₂=10.158, D₃/D₄=0.681, D₁/T=20.556, D₂/T=31.500,D₃/T=21.500, D₄/T=31.500, and in one preferred form of this embodimentD₁=0.370 inch, D₂=0.567 inch, D₃=0.387 inch, D₄=0.567 inch, L₁=0.036inch, L₂=0.038 inch, and T=0.018 inch.

It should be understood the valve 10 may find use with many differenttypes and constructions of closures, containers, and other sources offluent product, that a closure 40 is shown in FIGS. 4 and 5 for purposesof illustration, and that the particular form or construction of theclosure 40 forms no part of the invention unless expressly recited in anappended claim, For purposes of illustration, the closure 40 comprises abase 41 and a retainer 42. The base 41 includes a deck 43 having adispensing port 44 defined therein, and a skirt 45 extending downwardlyfrom the deck 43 and having retention and sealing features forengagement with a neck of a suitable container (not shown). The retainer42 includes a laterally outwardly extending annular lip or bead 46 thatforms a snap fit engagement with a laterally inwardly extending bead(s)or rib(s) 47 on an interior side 48 of the deck 43. To accommodatemounting and retention of the valve 10, the peripheral attachmentportion 19 preferably has a generally dovetail-shaped, transverse crosssection which defines a pair of frustoconical surfaces 50 and 52, asbest seen in FIGS. 2, 4, and 6. As best seen in FIG. 4, the deck 43includes a frustoconical surface 54 surrounding the port 44 for matinglyengaging the axially outwardly (e.g., exterior environment) facingfrustoconical surface 50 of the attachment portion 19, and the retainer42 includes a frustoconical surface 56 for matingly engaging the axiallyinwardly (e.g., interior environment) facing frustoconical surface 52.

While a preferred form of mounting has been shown, the attachmentportion 19 could have other configurations, many of which are known,that would engage with corresponding configurations on a closure,container, or other source of fluent product. Also, in some otherarrangements, the attachment portion 19 could be held by other means,such as, for example, heat bonding, material bonding such as is achievedin bi-injection molding, adhesive, and/or a press fit, etc.

It is to be understood that the orifice of the valve 10 may be definedby structures other than the illustrated straight slits 28. The slits 28may have various different shapes, sizes and/or configurations inaccordance with the requirements and parameters of each particularapplication. For example, the orifice may also include only one slit 28or three or more intersecting slits 28.

If it is desired to provide particular performance characteristics, thenthe valve 10 is preferably configured for use in conjunction with (1)the characteristics of the particular application, which, for example,may establish the maximum anticipated pressure differential across thevalve 10; (2) the characteristics of the particular substance or productto be used with the valve 10; and (3) any relevant characteristics ofother components, such as a closure or container. For example, theviscosity and density of the fluent substance can be relevant factors indesigning the specific configuration of the valve 10. The rigidity anddurometer of the valve material, and size and shape of the valve head10, can also be relevant to achieving some desired characteristics, andcan be selected for accommodating the normal range of pressuredifferential that is expected to be typically applied across the valvehead 10, and for accommodating the characteristics of the substance tobe used with the valve 10.

It will be readily observed from the foregoing detailed description ofthe invention and from the illustrations thereof that numerous othervariations and modifications may be effected without departing from thetrue spirit and scope of the novel concepts or principles of thisinvention.

1. A flexible, resilient, slit valve (10) to allow selective dispensingof a fluent product from an interior environment to an exteriorenvironment, the valve comprising: a flexible, resilient head (12)centered on a central axis (27) and extending laterally therefrom, thehead (12) having: a convex interior surface (16) to face an interiorenvironment (17), a concave exterior surface (14) to face an exteriorenvironment (15), at least one self-sealing slit (28) through the head(12), confronting, openable portions (30) along the at least one slit(28) to define a normally closed orifice in an unconstrained conditionwherein the openable portions (30) can move in a first direction towardthe exterior environment (15) to an open orifice configuration andreturn in an opposite direction to a closed configuration, and alaterally outwardly facing peripheral surface (18) extending from theinterior surface (16) toward the exterior surface (14), the peripheralsurface (18) centered on the central axis (27); an annular, peripheralattachment portion (19) centered on the central axis (27) and spacedlaterally from the head (12); and an annular, flexible, resilient,intermediate portion (20) centered on the central axis (27) andextending laterally from the head (12) to the peripheral attachmentportion (19), the intermediate portion (20) having: an interior surface(26) to face said interior environment (17), and an exterior surface toface said exterior environment (15); and wherein; the exterior surfaces(14, 24) of the head (12) and the intermediate portion (20) intersect ata first circular line of intersection (32) having a diameter D₁, theexterior surface (24) of the intermediate portion and the peripheralattachment portion (19) intersect at a second circular line ofintersection (34) having a diameter D₂, the second circular line ofintersection (34) is spaced in the first direction from the firstcircular line of intersection (32), the first and second circular linesof intersection (32, 34) lie in parallel planes extending transverse tothe central axis (27) and spaced from each other along the central axis(27) by a distance L₁, the ratio of D₁/D₂ is in the range of 0.600 to0.900 in an as-molded condition of the valve (10), and the ratio ofD₂/L₁ is in the range of 14.000 to 19.000 in said as-molded condition ofthe valve (10).
 2. The valve (10) of claim 1 wherein the exteriorsurface (24) of the intermediate portion (20) is convex and the exteriorsurface (14) of the head is concave and the first circular line ofintersection (32) is defined at an inflection point between the convexexterior surface (24) of the intermediate portion (20) and the concaveexterior surface (14) of the head (12),
 3. The valve (10) of claim 2wherein the ratio of D₂/L₁, is in the range of 15.500 to 16.000 in theas-molded condition of the valve (10).
 4. The valve (10) of claim 3wherein the ratio of D₂/L₁ is 15.750 in the as-molded condition of thevalve (10).
 5. The valve (10) of claim 2 wherein the ratio of D₂/L₁ isin the range of 18.500 to 19.000 in the as-molded condition of the valve(10).
 6. The valve (10) of claim 5 wherein the ratio of D₂/L₁ is 18.750in the as-molded condition of the valve (10).
 7. The valve (10) of claim2 wherein the ratio of D₁/D₂ is in the range of 0.625 to 0.675 in theas-molded condition of the valve (10).
 8. The valve (10) of claim 7wherein the ratio of D₁/D₂ is 0.653 in the as-molded condition of thevalve (10).
 9. The valve (10) of claim 2 wherein the ratio of D₁/D₂ isin the range of 0.800 to 0.850 in the as-molded condition of the valve(10).
 10. The valve (10) of claim 9 wherein the ratio of D₁/D₂ is 0.827in the as-molded condition of the valve (10).
 11. The valve (10) ofclaim 2 wherein the ratio of D₂/L₁ is in the range of 15.500 to 16.000and the ratio of D₁/D₂ is in the range of 0.625 to 0.675 in theas-molded condition of the valve (10).
 12. The valve (10) of claim 2wherein the ratio of D₂/L₁ is in the range of 18.500 to 19.000 and theratio of D₁/D₂ is in the range of 0.800 to 0.850 in the as-moldedcondition of the valve (10).
 13. The valve (10) of claim 2 wherein theintermediate portion (20) has a uniform material thickness separatingthe exterior and interior surfaces (24, 26).
 14. The valve (10) of claim2 wherein the interior surface (26) of the intermediate portion (20) isconcave and the peripheral surface (18) of the head (12) isfrustoconical.
 15. The valve of claim 1 wherein at least one of theinterior and exterior surfaces (14, 16) of the head (12) has a planarportion adjacent the central axis (27), extending transverse to thecentral axis (27).